A conventional and known cooling-type imaging device cools the imaging element by forming a through hole in a printed circuit board on which the imaging element is mounted and which is to be installed in a digital camera, in which the thorough hole is for exposing the back surface of the imaging element, and the through hole is for making a cooling means, which is a heat sink, for example, and which is located at a back surface side of the printed circuit board, come into direct contact with the back surface of the imaging element. (See Patent Literature 1, for example.)
Also, Patent Literature 2 discloses a technique in which copper foil pattern of the power supply terminals of the imaging element is utilized for heat dissipation when imaging elements are mounted on the front surface of printed circuit boards. (See Patent Literature 2, for example.)